Autoimmune Thyroid Disorder in Children and Adolescents with Type I Diabetes Mellitus

Type one diabetes mellitus (Type 1 DM) is the most common type of diabetes in children and adolescents, arising through a complex interaction of immune, genetic and environmental factors. Autoimmune thyroid disease is the most frequent disorder associated with Type one diabetes mellitus. This study aimed to evaluate incidence of autoimmune thyroid disease in children and adolescents with type I diabetes mellitus.
Cross sectional case control study was made on forty diabetic children with regular attending to the Endocrinology clinic and patients from pediatric ward in Al-Imamain Al-Kadhimain Medical City, Eraq, and forty healthy children matching in aged (1-15 years) and gender were taken as control. History taking, clinical examination, measurement of hemoglobin A1C, serum thyroid peroxidase autoantibodies and serum thyroid stimulating hormone levels were carried out. Serum thyroxine and triiodothyronine were measured.
Serum thyroid peroxidase antibodies was positive in 15 % of diabetic patients, while it was negative in controls. In those with positive thyroid peroxidase antibodies 100% had subclinical hypothyroidism, 50% had hyperthyroidism. Risk of autoimmune thyroid disease was more in patients older than 5 years and it was neither related to the degree of control of diabetes nor to the duration, but it was more common in females.
There is higher incidence of autoimmune thyroid disease in children and adolescents with type one diabetes compared with normal children and this risk is not related to duration of diabetes, but it is more common in those older than 5 years. The risk of hypothyroidism is double the risk of hyperthyroidism in these patients.